I have made many of these hats over the years, all from the same basic pattern. Most of them were made to demonstrate that the same mathematical principles will work with any yarn. The hats shown used a large variety of yarns, including one made from shredded M & S carrier bags.

We used to sell a booklet, which was written when I had just made a few. It really needs re-writing as there is much I can add now. I will get round to it one day!

October 2019
I did finally get round to it. The pattern is now available.